Apparatus for removing air from the head spaces of filled cans



J. M. BOYD ET AL APPARATUS FOR REMOVING AIR FROM THE HEAD SPACES OF'FILLED CANS Aug. 14, 1956 3 Sheets-Sheet 1 Filed March 17,. 1953 4.17.;www 00 La m .W

BY w ml MJfiorneys Aug. 14, 1956 J. M. BOYD ET AL 2,758,766

APPARATUS EoR REMOVING AIR FROM THE HEAD sPAcEs oF FILLED CANE FiledMarch 17, 1953 5 Sheets-Sheet 2 4] l jing. Z,

IN V EN T ORS Jfm M 30g@ A BOYD T AL 2,758,766

J. M. APPARATUS FOR REMOVI AIR FROM THE HEAD SPACES OF' FILLED CANSFiled March 17, 1953 3 Sheets-Sheet 3 figg. 4Z 59.6 5 a y 57 I Aug. 14,1956 l v Z0 lhwentors (ttornegs United States Patent O APPARATUS FORREMOVING AIR FROM THE HEAD SPACES OF FILLED CANS John M. Boyd, Chicago,Ill., and Frank W. Parrin, Whittier, Calif., assignors to ContinentalCan Company, Inc., New York, N. Y., a corporation of New YorkApplication March 17, 1953, Serial No. 342,852

`12 Claims. ('Cl. 226-68) The invention relates generally to the art ofcanning and to apparatus wherein filled cans are closed and sealed, andit primarily seeks to provide a novel means for displacing air from thehead spaces in filled cans just prior to the closing thereof and bydirecting a gaseous medium such as an inert gas into said head spaces ina manner for displacing the air and replacing the same with the inertgas.

It is well known in the canning industry that when air is sealed in canscontaining certain beverages and food products, said air has a badeffect on the products during the shelf life of the sealed cans, and itis therefore desirable to remove the air from the container head spacesprior to the sealing of the containers. This is not an entirely newprocedure. Attempts have been made to attain the stated end by variousmeans, as by the drawing of a vacuum or by force jetting, and even byintroduction of a gaseous medium such as an inert gas or steam. However,only partial success has been achieved in prior known practices. Someattempts have proven unacceptable because of failure to accomplish thedesired results at a commercially practical rate of speed. Attempts tospeed up the air displacement have revealed faults in the gaseous mediumdirecting devices resulting in incomplete air displacement,objectionable turbulence in the product and wastage of the gaseousmedium, and the development of aspirating effects serving to draw airinto the head spaces from which it is sought to displace the same. It isa purpose of the present invention to provide an apparatus capable offunctioning in a manner which will eliminate the difficulties referredto.

An object of the invention is to provide an apparatus of the characterstated wherein the gaseous medium is directed into and over the filledcan head space throughout substantially the whole width thereof in anevenly dispersed ribbon form and at relatively low velocity, thereby tosubstantially completely displace the air and replace the same with thegaseous medium without bringing about any objectionable turbulence inthe fill, and without drawing in of air as by an aspirating action.

Another object of the invention .is to provide an apparatus of thecharacter stated in which the even dispersion of the gaseous medium isaccomplished by directing the same toward the filled container headspace through a screen mesh.

Another object of the invention is to provide an apparatus of thecharacter Stated wherein the gaseous medium is directed toward thefilled container head space through a single open slot covered by ascreen mesh and extending in concentric relation closely :adjacent theopen 2,758,766 Patented Aug. 14, 1956 top of the can and aboutapproximately one third of the circumference thereof.

Another object of the invention is to provide an apparatus of thecharacter stated wherein the filled cans are moved along in theperipheral pockets of a rotary turret as they are having the airdisplaced therefrom, a can end or closure being centered over and spaceda short distance above each open can top, the gaseous medium beingdirected toward each filled container head space through an individualopen slot carried by the turret and covered by a screen mesh andextending about approximately one third of the circumference of ia canin the particular pocket at the level of the space between the open topof said can and the overlying closure.

Another object of the invention is to provide an ap paratus of thecharacter stated wherein the gaseous medium directing screened slotassociated with each turret pocket is placed to present the screen meshuprightly with a portion thereof extending above the outwardly directedflange of a filled can moving along in said pocket, and another portionthereof extending below said flange so that a part of the emitteduniformly dispersed ribbon of gaseous medium will pass over the open topof the can and beneath the overlying closure, and the remainder willcontact and pass downwardly against the can body wall in =a mannerassuring against any aspirating effect likely to draw air into the opentop of the can.

Another object of the invention is to provide an apparatus of thecharacter stated wherein the filled can circumference conforming,screened gaseous medium delivering slot opens outwardly from an arcuateslot which receives the gaseous medium from ia plurality ofequidistantly spaced, uprightly disposed orifices delivering fromanother chamber which is arranged arcuately and substantially concentricto the screened slot outlet.

Another object ofthe invention is to provide an apparatus of thecharacter stated wherein each screened gaseous medium delivering slot,the associated arcuate chamber and the communicating orifices are formedin a unitary, individually mountable and removable nozzle structure.

With thev above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by referenceto the following detailed description, the appended claims and theseveral views illustrated in the laccompanying drawings.

In the drawings:

Figure l is a somewhat diagrammatic plan view and part horizontalsection illustrating an embodiment of the invention.

Figure 2 is an enlarged fragmentary vertical section taken on the line 22 on Figure 1.

Figure 3 is a diagrammatic plan view illustrating one acceptable meansfor driving the associated turret shown in Figure 1.

Figure 4 is an anlarged fragmentary vertical longitudinal sectionlooking into one turret pocket opposite the screened outlet throughwhich the gaseous medium is directed into the pocket against and overthe open mouth or top of a can, a can end or closure being shown asmoving into place over the pocket, the latter being shown as devoid of acan for clarity of illustration.

Figure 5 is a detail plan View .illustrating one ofthe gaseous mediumoutlet plates, a portion of the cover section thereof being broken awayto 4show the. scre en coveredy outlet and the gaseous. medium chambertherebeneath to better advantage.

Figure 6 is a central vertical cross section taken through the plate ofFigure 5.

Figure 7 is a left end elevation of the plate shown in Figure 5.

In the somewhat diagrammatic illustration in Figure 1, there is shownone practical adaptation of the invention as a means for directing agaseous medium against and over the open tops of filled cans fordisplacing air from the) head'y spaces therein as the filled' cans and'can end or closure complements are being rapidly fed to the closingmachine, provisionr being made for holding the closures inhorizontalposition inst above and centered over the open topsV of thecans, and' for directing the gaseous medium in the formY of a uniformlydispersed, non-agitating ribbon wholly across said open can tops and incontact beneath thel loverly-ing closures until the initiai assembly ofeach can andY closure complementI is completed, and immediately inadvance of; the commencement of the double seam sealing of the cans.

While reference is made herein to displacement of the filledI can headspace air by proper direction and dispersion of an inert gas such asCO2, it is' to be understood thaty the disclosed apparatus may be usedin like manner for directing other inert gas, or steam into the cans forthe stated purpose. When an. inert gas is to bel usedas` the airdisplacing medium it is preferred that the apparatus beequipped withsome satisfactory form of'no-cankno-gas valve means in order to avoidunnecessary use of the gas, despite the economies in use of such gasmadepossible by employment of: the particular form or' apparatushereindisclosed.

Inthei-llustration'in Figure l, a lled can feeding means is shown andgenerally designated A, the can endsl are fed one-by-one from anysuitable can end feeding means (not shown) located at the can endlfeeding stationV B, a marker of any approved form (not shown) may beemployed at the marking station C for marking the can ends prior toassembly with the cans, the cans withthe closures thereover are rapidlyconveyed' by the canand closure transferring turret generally designatedD, the inert gas flow control!l valve means isgene-rall-ydesign-ated E,and the closing and' discharging turrets of' a six-spindle closingmachine are diagrammaticall-'y indicated, the closing turret beinggenerally designated F4 and the closed cany discharging turret beinggenerally designated G.

While any suitablemeans may be providedV for driving the cooperatingparts in suitably timed relation, an ac'- cept-able drive arrangement isdiagrammatically illustrated in Figure 3 wherein the main drive gear isindicated at- 5. I`tisv to be understood thatl rotation may beimparteci' to the shaft on which the gearV 5? is ailxed in any approved'man-ner (not shown). The drive gear 5 may serve to= drive an idler gear6 which is rotatable with an idler gear '7' disposed to mesh with andimpartv rotation to a gear 8 which may be connected in drive relation.lwith the driver shaft (not shown): through.- which rotation is impartedto the cover feed devices at station B. The driver gear also impartsrotation to the cl'osing turret and drive gear 9' mounted' to:` rotate.with the: driver gear 10 which meshes with and drivesv the:transfer'tu-rret driver* gear 11 and?` also` the discharge turretdrivergear lf2. The-markerreferred to generally herein is not absolutelyessential and therefore a means for driving the same: is not shown andmay take any acceptableform. The transfer-turret D includes a centralhub 1 3`L whereon the turret platey 114 is secured. This turret has aplural-ity of peripheral pockets or half moldsx 1-5, six being shown,and' these are disposed to receive the filled cans asl they are fedalong by the can feeding means generally desig-y nated A. See Figure 1.The turret D is equipped with a topface shelf or recess 16 at'theyposition of eachpocket whereon a gassing block or' nozzleV 1 '75 isremovably secured, as by cap` screws 18.

It will be observedy that each of. the gassing blocks, or nozzlesgenerally designated 17 includes an arcuate face 19 which bearsconcentric relation to the associated turret pocket and is stepped backfrom the pocket wall so as to provide a can flange clearance in themanner clearly illustrated in Figure 2. Each block or plate 17 also isequipped with an arcuate slot 20 which opens through the bottom facethereof in position for bearing concentric relation to the associatedturret pocket wall and communicating with the outer leg 21 of a radialfluid duct 22 formed in the turret plate 14. The turret plate isprovided with six cquidistantly spaced ducts 22, one for serving eachgassing block' or nozzle 1'7, and each said duct includes an innervertical leg 23 which opens, through the top surface of the turretplate. All of the vertical legs 23 or inner duct terminals are arrangedin a circler for a purpose that Will become apparent as thisdescription. progresses.

It will be yobserved by reference to Figures 4 through 7 that thearcuate slot 20 im the-under surface of each` block 17 is sort ofL-shaped in vertical cross section and placed to present an inner deepchamber portion 24, which directly overlies the gassing duct outlets 21,and an outer shallow chamber portion 25. Each block also has anarcuaterecessy 26- in its top surface and extending through its turretpocket aligning outer wall in such position as toj provide a shelf orintermediate horizontal wall 27 overlying the shallow chamber portion ofthe arcuate slot 20. Each shelf 27 defines the bottom of an arcuate gasdelivery or outlet chamber 28' which communicates with the underlyingshallow chamber portion 25 through a plurality of equidistantly spacedorifices 29 extending upwardly through the shelf 27, and each chamber28,

though openingoutwardly into the associated turret' pocket throughapproximately one third of a can circumference, is. closed' at the topby a can endv supporting closure plate 30' which seats in a shoulderrecess 31 formed in the block and is removably secured on the block, asYby screw means 32'. The turret pocket opposing outer faces of each block17 and its outlet chamber closure plate 30 are arcuately recessed toreceive a gas. directing and dispersing screen 33 which serves to veryuniformly disperse the gas as it is deliveredv through the chamber 28into the turret* pocket, as will be apparent by reference to Figures 1,2, 4 and 5.

At theposition of each turret pocket 1'5, the turret pIate 14 is'equipped with two lugs, a high lug 34' at the trailing side of thepocket, and a low lug 35 at the advance side, of the pocket. The lugs ofeach set are cooperatively spaced in the manner illustrated in Figures land 4 of the drawings so as to accurately center a can end or closure 36between them in the direction in which the closure is being conveyed bythe transfer turret D'. Other means for guiding and holding the closures316 in a manner for accurately placing them over the open topped filledcans will be described hereinafter.

By reference to Figures l and 2 it will be apparent that the turretplate 14' is centrally recessed to receive thevvalve core 37"which isequipped with six. equidistantly spaced, uprightly disposedv duct bores38' registering with the before mentioned inner vertical legs 23' of theradial gassing ducts 22'. At their upper ends the bores 38 open radiallyoutwardly through the periphery of the valve core 37. A bushing sleeve39l surrounds the core 37 within a stationary housing 40" and'is closedat its upper end by a spring pressed plate 41, the housing being securedin any approved manner to the stationary turret guard plate 42 The`sleeve- 39l is provided with an arcuate gas slot 43 which extends onehundred twenty degrees about theI valve core 37:'. This arcuate slotcommunicates with a gas: supply` pipe 4`4- and it will bel apparent thatduringI rotation* of' the turret structure gas will.' bey delivered fromtion during which the e'spective ducts 23 communicate with thestationary arcuate gas slot 43.

In passing to the pockets l5 of the transfer turret D the filled cans 45with their conventional outwardly turned upper end iianges 46 are fedover a support or feedway 47 by a chain conveyor 48, being guided by anoutside rail 49. The rail 49 may include a curved end section bearingconcentric relation to the turret and cooperating with a fixed railsection 50 in outwardly conlining the travel of the cans until they aredelivered onto the pads of the closing machine and into position forbeing cooperatively engaged by the pockets of the closing machine in thewell known manner. See Figures 1 and 2.

As each cover or can end closure 36 is dropped by the diagrammaticallyillustrated screws 51 of the closure feed means at station B it fallsupon inner and outer support tracks 52 and 53, to be conveyed thereoverby the oncoming high turret lug 34 in proper alignment over theparticular turret. pocket 15.

The undersurface of the turret guard plate has secured thereto an innercover guide rail 54 which is stepped to present an inner cover guidingand conning surface 55 which is concentric to the center of the transferturret. The stepping of the rail also provides a raised ceiling wall 56which is shaped in the manner clearly illustrated in Figure 4 to providea high level portion 57, a low level portion 58 and a connectingdownwardly inclined portion 59. A plate section 60 secured beneath theguide rail 54 projects outwardly beyond said rail to provide a coversupporting ledge or shelf shaped to provide a high level portion 61 onthe same plane with the inner track 52, and a downwardly inclinedportion 62 the discharge end of which drops the covers fed successivelythereover onto the underlying and aligned turret pocket gassing nozzleclosure plate 30, as shown in Figures 2 and 4. An outer guide rail 63 issecured beneath the turret guard plate 42 and is stepped to provide anouter cover guide conning surface 64 which is concentric to lthe turretaxis and cooperates with the previously mentioned rail surface 55 andthe pocket lugs 34 and 35 in accurately centering the can closures orcovers 36 in the manner previously described. lt is to be understoodthat the outer guide rail 63 is shaped like the inner rail 54 to providehigh level, low level and intermediate downwardly inclined ceilingportions as described at 57, 58 and 59 in Figure 4, and a plate 65 issecured to the bottom surface of the rail 63 to serve a purposecomparable to the previously mentioned plate section 60, and also toprovide a narrow edge curl supporting ledge extension 66 as shown inFigure 2. The inner and outer rails 54 and 63 are spaced apart as at 67to provide a clearance through which the cover feeding and positioninglugs 34 and may pass in the manner clearly illustrated in Figure 2.

At the position of the downwardly inclined portions 59 of the rails theturret guard plate 42 is recessed to receive an arcuate retarder shoe 68which is spring depressed at 69 and serves to engage and retard theconveyed closures 36 in the manner shown in Figure 4. This retardingaction causes the individual covers 36 to move accurately down intoposition between the lugs 34 and 35 of each conveying and aligning lugset and assures against covers being engaged by the respective rapidlytravelling conveyor lug 34 and bouncing oif the same forwardly intoposition for jamming over the advance or positioning lug 35.

It will be apparent from the foregoing, and by reference to Figures land 2, that the can closures 36 are held in horizontal positionaccurately centered and spaced above the filled cans they are to close,and this relation of each can and cover complement will pertain untilthe can is transferred onto the receiving pad 70 of the closing machineturret F shown diagrammatically in Figure l. Promptly after each can isreceived on the particular .turret pad the pad lifts the can intocontact with the overlying cover, and the can and cover complement thusinitially assembled, into contactywith the chuck of the sealing devicesin the manner Well known in the art. It will be apparent by reference toFigure l that the gaseous medium supply slot 43 extends around to apoint where communication therewith of the radial turret supply ducts 22will permit continuation of the directing of the gaseous medium throughthe screened delivery slots right up to and through progression of theinitial assembly of the can and cover complements previously referredto.

l't is to be noted that the top surfaces of the nozzle blocks I7 havearcuate recesses 71 in their upper inwardly presented surfaces whichbear concentric relation to and clear the inner closure edge guiding orconfining wall 55.

,- See Figures l, 2, 5 and 6.

Attention is directed to Figure 2 wherein the relation of the flanges 46of the cans with the screened, gaseous medium delivering slots is shown.It will be noted that said flanges are disposed just below thehorizontal centers of said slots. By reason of this positioning of theparts, the gaseous medium is caused to split at the can lianges so thatsome thereof will be diverted downwardly about the exterior of the cansbelow the flanges. By this causing of some of the gaseous medium to passdownwardly over the external surfaces of the cans in the transfer turretpockets 15, any movement of air upwardly about the cans and into theinteriors thereof is avoided. In other words, any aspirating effect ofthe unformly dispersed body or ribbon of the gaseous medium passing overand into the open tops of the cans beneath the overlying covers 36 whichwould tend to draw air upwardly and over the can flanges 46 into theinteriors of the cans is avoided.

As before stated, each gaseous medium delivering slot 26 and itsscreened outlet 33 extends about approximately one third of thecircumference of a can being conveyed by the associated transfer turretpocket. It will be noted also by reference to Figure 5 that the sideterminals 72 of each said slot are disposed in generally parallelrelation and are spaced apart a distance approximating the insidediameter iof a can. The purpose of this is to assure that the body ofgaseous medium emitted from each nozzle slot 26, uniformly dispersed bythe screen 33 in the form of a ribbon expanding slightly horizontallyand laterally as it passes out over the end walls 72 of the slot, willcompletely traverse and fill and crowd out air from the filled can headspace throughout the full width and depth thereof, replacing said airWith the gaseous medium so that upon prompt sealing of the can in themanner aforesaid, the gaseous medium filling the head space will besealed therein.

It has been found that the herein disclosed gaseous medium deliverynozzle operates in a very eicient manner. The displacement of the headspace air is substantially complete because of the manner of directingthe gaseous medium and the action of the screen in uniformly dispersingthe same in a continuous,l unbroken ribbon. Moreover, the action ofdisplacing the air is a gentle crowding action rather than a highpressure blowing out of the air. Consequently the gaseous medium isdelivered at low velocity, say for example, four ounces of pressure oreven less, and therefore wastage of the gaseous medium is negligible,and objectionable stirring up of a turbulent condition in the can iillis avoided.

Outlet screens of varying total open area have been found practical inthe efficient delivery and uniform dispersion of the gaseous medium, andthese screens provide greater open area and more uniform dispersion ofthe gaseous medium than is possible in the presently known equipmentsemploying orices or slots in the delivery of the gaseous medium. Screensranging from forty mesh having a thirty-four percent pore area to eightymesh having thirty one and four tenths percent pore area have servedefficiently in displacing air from the head spaces in varied sizes ofcans iilled with various products.

. While an example structure and mounting `of the screened nozzle isdisclosed herein it is to be understood that variations in the structureand arrangement of the nozzle may be provided without departing from thespirit and scope of the invention as defined in the appended claims.

We claim:

l. A gaseous medium delivery nozzle structure of the character describedcomprising a face uprightly disposed and arcuate in shape to bearconcentric relation close to the exterior of a can to be treated by thedelivered gaseous medium, a gaseous medium delivery slot extendingthrough said face and of a length for extending without interruptionabout approximately one third of the circumference of a can disposedopposite and in concentric relation to said face, and a gaseous mediumdelivery chamber extending the full length of said slot for deliveringthe gaseous medium therethrough, means for directing a gaseous mediuminto said chamber, and a mesh screen uprightly disposed and coveringsaid slot at the outlet therefrom and through which gaseous mediumdirected through the slot is uniformly dispersed in the form of acontinuous ribbon.

2. A gaseous medium delivery nozzle structure of the character describedcomprising a face arcuate in shape to bear concentric relation to theexterior of a can to be treated by the delivered gaseous medium, agaseous medium delivery slot extending through said face and of a lengthfor extending about approximately one third of thecireumference of a candisposed opposite and in concentric relation to said face, and a gaseousmedium delivery chamber extending the full length of said slot fordelivering the gaseous medium therethrough, means for directing agaseous medium into said chamber, and a mesh screen covering said slotand through which gaseous medium directed through the slot is uniformlydispersed in the form of a continuous ribbon, said gaseous mediumdelivery chamber being arcuate in shape, and said means for directing agaseous medium into said chamber including a second chamber overlappingsaid delivery chamber in vertically spaced relation thereto to providean intervening wall portion, and there being ineluded equidistantlyspaced oriiices extending uprightly through said wall portion todistribute the gaseous medium into the delivery chamber from the otherchamber to expand therein before passing through the screen.

3. A nozzle structure as defined in claim 2 wherein the gaseous mediumdelivery chamber is dened at its ends by two walls bearing generallyparallel relation and spaced apart a distance approximating the insidediameter of a can to be treated by the delivered gaseous medium.

4. A gaseous medium delivery nozzle structure of the character describedcomprising a face arcuate in shape to bear concentric relation to theexterior of a can to be treated' by the delivered gaseous medium, agaseous medium delivery slot extending through said face and of a lengthfor extending about approximately one third of the circumference of acan disposed opposite and in concentric relation to said face, and agaseous medium delivery chamber extending the full length of said slotfor deiivering the gaseous medium therethrough, means for directing agaseous medium into said chamber, and a mesh screen covering said slotand through which gaseous medium directed through the slot is uniformlydispersed in the form ofv a continuous ribbon, said gaseous mediumdelivery chamber being defined at its ends by two walls bearinggenerally parallel relation and spaced apart a distance approximatingthe inside diameter of a can to be treated by the delivered gaseousmedium, said gaseous medium delivery chamber being arcuate in shape, andsaid means for directing gaseous medium into said chamber including asecond chamber overlapping said delivery chamber in vertically spacedrelation thereto to provide an intervening wall portion, and there beingincluded equidistantly spaced orifices extending uprightly through saidwall portion to distribute the gaseous medium into the delivery chamberfrom the other chamber to expand therein before passing through thescreen.

5. In apparatus of the character described, a transfer turret havingthereon a gaseous medium delivery nozzle structure comprising a flatplate-like body having a gaseous medium delivery chamber therein and adelivery slot opening outwardly from said chamber through an uprightdelivery face portion of the body, means on said turret and at least inpart including said .nozzle for supporting and moving a filled can and acomplementary cover spaced slightly and horizontally thereover inposition for having a gaseous medium delivered from said slot passhorizontally over the open top of the can and beneath said cover, meansfor directing a gaseous medium into said chamber for delivery throughsaid slot, and a mesh screen covering said slot and uprightly disposedin close proximity to the exterior of a can being so moved and throughwhich the gaseous medium is uniformly dispersed in the form of acontinuous ribbon into the open top of said can.

6. Apparatus as deiincd in claim 5 in which the slotted delivery faceportion of the body is arcuate in shape to bear concentric relation tothe exterior of the filled can and the slot and screen are of a lengthfor extending about approximately one third of the circumference of thecan.

7. Apparatus as defined in claim 5 in which the slotted delivery faceportion of the body is arcuate in shape to bear concentric relation tot'he exterior of the lled can and the slot and screen are of a lengthfor extending about approximately one third of the circumference of thecan and wherein the gaseous medium delivery chamber is defined at itsends by Walls bearing generally parally relation and spaced apart adistance approximating the inside diameter of the can.

8. Apparatus as defined in claim 5 wherein the filled can supportingmeans bears such relation to the gaseous medium delivery slot that thecontinuous ribbon of the gaseous medium delivered through the screenthereover will split on the flange at the top of a conventionally angedcan being treated so that a part of said ribbon s will contact and passdownwardly against the can body wall in a manner assuring against anyaspirating effect likely to draw air into the open top of the can.

9, In apparatus of the character described, peripherally pocketed rotaryturret means for conveying iilled can and cover complements toward aclosing means with each cover disposed over the open top of thecomplementary can in` spaced relation, and means for delivering agaseous medium into the space between the cover and open can top of eachcan and cover complement as they are being conveyed for displacing airfrom the can head spaces, said delivery means including a nozzlelstructure on the turret at the position of each peripheral pocket andcomprising a plate-like body having a face arcuate in shape to bearconcentric relation to the exterior of a can in the respective pocket, agaseous medium delivery slot extending through said face and of a lengthfor extending about approximately one third of the circumference of saidcan, a gaseous medium delivery chamber extending the full length of saidslot for delivering the gaseous medium therethrough and a mesh screencovering said slot and through which gaseous medium directed through theslot is uniformly dispersed in the form of a continuous ribbon, andvalve means for controllingv the ilow of` gaseous medium to saiddelivery chambers.

l0. Apparatus as deiined in claim 9 wherein there are included means forso placing the cans as they are being conveyed that the continuousribbons of the gaseous medium delivered by the individual screened slotswill splitl on the flanges at the tops of conventionally jfiangedindividual cans so thatl a part of each said ribbon will contact andpass downwardly against the respective can body wall in a mannerassuring against any aspirating effect likely to draw air into the opentop of the can.

11. Apparatus as defined in claim 9 wherein each gaseous medium deliverychamber is defined at its ends by walls bearing generally parallelrelation and spaced apart a distance approximating the inside diameterof the cans being conveyed.

12. Apparatus as defined in claim 9 wherein eac'h gaseous mediumdelivery chamber is arcuate in shape and is defined at its ends by wallsbearing generally parallel relation and spaced apart a distanceapproximating the inside diameter of the cans being conveyed, andwherein 10 each nozzle structure also includes a second arcuate chamberbearing concentric relation to the delivery chamber and overlapping thesame in spaced relation to provide an intervening wall portion piercedby equidistantly spaced oritices effective to distribute the gaseousmedium into the delivery chamber from the second chamber wherein it isinitially received through the valve means.

References Cited in the le of this patent UNITED STATES PATENTS

